Determination of total fatty acids

1931 ◽  
Vol 8 (1) ◽  
pp. 23-25
Author(s):  
A. K. Church
2014 ◽  
Vol 87 (3) ◽  
pp. 516-525 ◽  
Author(s):  
Atsushi Watanabe ◽  
Chu Watanabe ◽  
Robert Freeman ◽  
Mari Nakajima ◽  
Norio Teramae ◽  
...  

ABSTRACT Determination of stearic acid in rubber is very important from the viewpoint of quality control of products. In place of the conventional liquid-phase extraction procedures for the analysis of additives in rubber, stearic and palmitic acids in vulcanized styrene–butadiene rubber (SBR) samples were directly analyzed in the solid state by thermal desorption (TD)–gas chromatography (GC)/mass spectrometry (MS) and thermally assisted hydrolysis and methylation (THM)–GC/MS. It was found that the precision of analytical data was only fair in the TD-GC/MS analysis, with 7.8% relative standard deviation (RSD), because of the interaction between the polar fatty acids and basic sites in the GC chromatographic system. On the other hand, THM-GC/MS, in which the fatty acids are derivatized to the methyl esters using tetramethylammonium hydroxide, can overcome this problem. Under the optimized measurement conditions of this study for THM-GC/MS, the average determined value (0.62 wt%) of total fatty acids in the SBR samples was found to agree well with the compounded amount (0.64 wt%) used in the preparation stage of the SBR samples, and the RSD was 3.2%.


1951 ◽  
Vol 29 (5) ◽  
pp. 239-244
Author(s):  
Edouard Pagé ◽  
Loraine Michaud

A method is described for the determination of total fatty acids in small amounts of blood plasma. The plasma lipids are extracted in an alcohol–acetone mixture. Following saponification and hydrolysis, the fatty acids from an aliquot of their benzene solution are dissolved in alcoholic thymol blue and titrated with tetramethyl ammonium hydroxide as recommended by Schmidt–Nielsen. The method is applicable to the study of alimentary hyperlipemia in rats.


1935 ◽  
Vol 29 (7) ◽  
pp. 1677-1682 ◽  
Author(s):  
Corbet Page Stewart ◽  
Edward Bruce Hendry

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